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Paul
Crazy Horse

USA
776 Posts

Posted - 13 Nov 2010 :  3:08:53 PM  Show Profile  Reply with Quote
I read in a recent post in regards to forged rods from a 58 to 62 pontiac,the earlier post asked if these rods are good, and responses said they are called soft rods, therfor no good. I bought a set from a 1960 tempest and had them reconditioned, shot peened, (not heat treated)fitted with ARP studs. I dont know if the boss is 1-15/16 or 2" they did have the poor GM in the I-beam so im gonna gues they are 1-15/16. per John Angeles/Pete McCarthy Pontiac Racers hand book, these rods should be plenty strong. After the fact, I found this site and have bought Jim Hands book, and no where in the book does it say anything about older Pontiac rods, and there use. in the post I read they may not be strong enough. the engine is a 74 455 with #13 heads with 72 c.c chambers.the engine has speed pro forged pistons on them. the calculated compression ratio is between 11- 11.5 to one. the engine should put out around 500+ H.P. with the cam intake and carb ect. My question is, are these rods going to fail? or befor I scatter the engine should I change things? the car is a 77 TA Street/Strip.

dgray
Crazy Horse

845 Posts

Posted - 13 Nov 2010 :  4:09:51 PM  Show Profile  Reply with Quote
Uh there was no '60 Tempest. The first one was in 1961.
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cortcomp
Coyote

USA
5464 Posts

Posted - 13 Nov 2010 :  4:46:16 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
What kind of fuel do you plan on running when you're driving around the street? Only reason i ask is that i would have bought race gas if it was cheap enough when i had the 670 heads on. Would have rather done that then all the head work/swapping to get the compression ratio down.
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Paul
Crazy Horse

USA
776 Posts

Posted - 13 Nov 2010 :  6:00:43 PM  Show Profile  Reply with Quote
ok maybe it was a 61 Tempest. it was a 60 389, either way, the rods fall under the 58 to 62 catagory as far as rods are concerned.. Im not here to be corrected, just asking. I plan on running the required fuel to get the octane up, to run this 77 TA as damn fast and hard as I can. ive already got that figured out! money is no object here, the engine is already built. so, with that, just wanting to know if these rods are a failure or not.
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mike mcarthur
Pony that Jumps

USA
2475 Posts

Posted - 13 Nov 2010 :  8:27:48 PM  Show Profile  Visit mike mcarthur's Homepage  Reply with Quote
There is no way I would use a going on 50 year old rod in anything. Prices on new ones are very reasonable so why take a chance? We just put together the numbers match engine for my GTO and put new rods in it, and it is essentially a restoration engine, but I'm not taking a chance on it. Just my .02

It's the stuff you learn after you know it all that's important
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Paul
Crazy Horse

USA
776 Posts

Posted - 13 Nov 2010 :  9:18:10 PM  Show Profile  Reply with Quote
yea, I know what you meen about using 50 year old parts. all im doing is new to me, and I went by what I read at the time.im not afraid of using 50 year old plus parts as long as they havnt been abused. and the machine shop said the rods looked great. i was fine with that. The car wont be driven til probably next summer so I guess we will see if they hold up, because once I feel the rings and all else is broke in, we are going to stomp on it. I would rather change things now though, instead of a big boom.
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Mr. P-Body
Running Bear

USA
2258 Posts

Posted - 15 Nov 2010 :  08:08:57 AM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Paul,

These rods are the "rubber" rods. Avoid them, trust me. For the $275 is takes to replace them with NEW 5140 forgings, there's no good reason to gamble. The new bolts for the rubber rods are about $70. Re-sizing 8 rods is $120. You are now "knocking on the door" of the cost of the new ones, and will still end up with a broken rod.

If your machine shop is familiar with the Pontiac, they won't base ANYTHING on how they "look" and they too, will highly recommend replacement. Have them "Rockwelled" and you'll see why they "gotta go".

Believe me. I have heard every rationalization known to man for NOT replacing them. The FACT is, machine shops make more money rebuilding your old ones than they do selling you new ones. Money is NOT "why" we tell you to replace them. Old Pontiacs are getting too scarce to sacrifice them for a few bucks.

FWIW

Jim

Edited by - Mr. P-Body on 15 Nov 2010 08:10:19 AM
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mike mcarthur
Pony that Jumps

USA
2475 Posts

Posted - 15 Nov 2010 :  09:21:33 AM  Show Profile  Visit mike mcarthur's Homepage  Reply with Quote
Ditto that. This is one of the many, many reasons I like Jim. He could be rebuilding old rods all day long but doesn't. You have to ask yourself if it's really worth trashing a block to use those rods. I say no way.

It's the stuff you learn after you know it all that's important
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sixt8bird
Chief Many Horses

USA
1114 Posts

Posted - 15 Nov 2010 :  12:22:32 PM  Show Profile  Visit sixt8bird's Homepage  Reply with Quote
http://www.pacificperformanceracing.com/products/pistons-rods-rings-bearings.html
Here is a Compny that is very instramental in bringing us new and improved Pontiac stuff. The link is for the rods but you might look at a full rotating assembly.
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goatasaurus rex
Sitting Bull

160 Posts

Posted - 17 Nov 2010 :  12:41:01 PM  Show Profile  Reply with Quote
jim, how did i get away with using a set of those with heavy trw pistons and pins. could they have been early sd rods? have crisp GM on them.
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Mr. P-Body
Running Bear

USA
2258 Posts

Posted - 17 Nov 2010 :  1:34:28 PM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote


The SD rods measure 2" from bolt boss to nut boss. A "well defined" "GM" is what HO Racing says to look for on the SD rod. The "rubber" rod and 421HO rods measure 1 15/16" boss-to-boss.

We hear about cast rods that "live" for years at higher revs, too. It happens. It is NOT "the norm". In today's engine "arena", it makes no sense to roll the dice.

Jim
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Paul
Crazy Horse

USA
776 Posts

Posted - 22 Nov 2010 :  10:48:02 AM  Show Profile  Reply with Quote
thanks for the info guys. I wish I knew this before, oh well. I do plan on putting in a different cam so while im there may as well replace these rods befor we run it hard. I have been told by a shop that taking press fit pistons off and putting them back on can distort them, is this true? These pistons are forged aluminum.
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Mr. P-Body
Running Bear

USA
2258 Posts

Posted - 23 Nov 2010 :  08:16:32 AM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Paul,

Pressing the pistons off can be a bit of a "crap shoot". For the most part, Pontiac pistons have a nice "flat" on each side, making it a little eaier to "support" than some others. If the pressing involves ONLY the pin, rod and bottom portion of the piston, everything SHOULD be okay. We always tell customers there's an "outside" chance the piston can be damaged. About one in every hundred or so we press gets distorted. As long as the pin bores aren't scratched, and the pin can move in and out freely (without the rod), everything is fine. A "swish" on the horizontal hone can repair MINOR distortion.

Jim
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Paul
Crazy Horse

USA
776 Posts

Posted - 29 Nov 2010 :  10:43:33 AM  Show Profile  Reply with Quote
5140 rods are the way to go then. any suggestions as to what brand? thank you
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Mr. P-Body
Running Bear

USA
2258 Posts

Posted - 29 Nov 2010 :  1:08:27 PM  Show Profile  Visit Mr. P-Body's Homepage  Reply with Quote
Paul,

RPM is the only 5140 rod "out there" I know of. PPR sells it as "Tomahawk". Same rod, same box, different label. If anyone else is aware of a different offering, I'd REALLY like to know about it! Nothing "wrong" with these rods, just would be nice to have alternatives. The old C.A.T. rods seem to have gone bye-bye...

Jim
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Paul
Crazy Horse

USA
776 Posts

Posted - 29 Nov 2010 :  2:15:07 PM  Show Profile  Reply with Quote
H beam or I beam? what about 4340 eagle rods, are they any good?
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455rocket
Tribal Scout

1 Posts

Posted - 09 Feb 2019 :  08:32:42 AM  Show Profile  Reply with Quote
old thread but some misinformation here...
the 1958-62 Pontiac forged rods are a good alternative forged rod.
they have been used for decades, literally since the 1970's, in Super Stock NHRA record holding cars making 600HP- wheel standing launch cars that ran low-10's and high 9's in the 1/4 mile.
how bad can the rods be ?
the reputation as "rubber rods" came about due to some guys taking the 1955-57 older rods and trying to run them for the same purpose. there's a difference. the 55-57 rods were an inferior grade steel.
the 58-62 rods were sae 1140 steel, and can be heat treated to 32-35 Rockwell "C" scale, the same hardness as the best SD455 8640 rod.
consider you can get the 58-62 rods for almost free now, they are a great deal. I got a set of 8 for $15. rod bolts are $62 from ARP. heat treating is $85 for a set of 8. then shot peen, resize.
for $200 you have a MADE IN USA forged rod that is as good as/better than the crap Chinese offshore forgings that cost $400 or more.
and the 58-62 rod won't devalue your engine.
any Pontiac engine with Chinese crank, rods in it, is hard to sell and must be sold at a discount to dump it. that offshore stuff devalues a car or engine terribly. nobody is really too fond of having to run it, and they do so out of necessity, not preference. the Chinese stuff has become racers throwaway parts, not exactly something you'd brag about while leaning on the fender trying to sell your car, or selling a used engine you no longer need.
I'd prefer made in USA vintage GM parts any day over Chinese repops, why are you guys recommending Chinese parts in this day and age ?
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tjs44
Crazy Horse

USA
610 Posts

Posted - 09 Feb 2019 :  11:07:30 AM  Show Profile  Reply with Quote
455rocket,I beg to diff with you.58-62 rods are NOT good HiPo rods!They need to be heat treated to be worth a damn.The 61-63 421 SD rods are better.The offshore rods from the likes of Molnar are FAR better than any pre 455SD rod.JMO,Tom
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Corncob2061
Cochise

USA
467 Posts

Posted - 09 Feb 2019 :  10:40:27 PM  Show Profile  Reply with Quote
For interest, here is a picture comparison, left are the 58-62 early, middle are the common cast, right are 455 SD

[URL=https://s350.photobucket.com/user/jaystukenholtz/media/Pontiacrodcomparison_zpshlhlqojm.jpg.html][/URL]
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tjs44
Crazy Horse

USA
610 Posts

Posted - 09 Feb 2019 :  10:43:30 PM  Show Profile  Reply with Quote
I would take a stock cast rod over a 58-62 forged rod EVERY day!Tom
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Corncob2061
Cochise

USA
467 Posts

Posted - 09 Feb 2019 :  10:51:09 PM  Show Profile  Reply with Quote
X2 on the cast rods over the early, Here is my experience with the early rods.


[URL=https://s350.photobucket.com/user/jaystukenholtz/media/pontiacrodbreak_zpsqqgoqgc8.jpg.html][/URL]


Edited by - Corncob2061 on 09 Feb 2019 10:54:14 PM
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Corncob2061
Cochise

USA
467 Posts

Posted - 09 Feb 2019 :  11:01:17 PM  Show Profile  Reply with Quote
I asked Jim Butler about this once for using the old rods. He said they did use to use them in some high hp stuff years and years ago because they were lighter than the Early SD rods. But he followed that statement by saying they spent well north of 1000 dollars to run them. Some place in Texas worked then over for them. IRC, they x rayed, shot peened and heat treated them. Jay

Edited by - Corncob2061 on 09 Feb 2019 11:19:38 PM
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Corncob2061
Cochise

USA
467 Posts

Posted - 09 Feb 2019 :  11:25:53 PM  Show Profile  Reply with Quote
Notice how thin the flange is coming off the rod journal area on those early rods, and it stays thin all the way up the rod.

I remember being pretty shocked when I tore that engine apart. Always wondered which rod gave up first in that picture. My guess is it was the middle, most beat up rod. Looked like it pulled the I beam in two? Jay

Edited by - Corncob2061 on 10 Feb 2019 12:01:03 AM
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Corncob2061
Cochise

USA
467 Posts

Posted - 09 Feb 2019 :  11:58:11 PM  Show Profile  Reply with Quote
We ran 2 other engines with cast rods and ARP bolts in the same car. The carnage picture was a 455 with a small solid cam, we thought the lighter weight forged early rods would help turn a few more RPM. LOL, did not work out for us. We ran a 350 with cast rods and ARP rod bolts with a solid roller cam, and a 466 with a bigger flat tappet cam and cast rods and ARP bolts, both those held together. The engines were pushed past 6000 sometimes at the end of the straights. This was in the 90's, we were pretty limited on rod options, SD rods were not in the budget. Jay

[URL=https://s350.photobucket.com/user/jaystukenholtz/media/3b58cc58-c7a2-4a16-8ac1-23e9f8ba94e6_zpsc7ledg9a.jpg.html][/URL]

Edited by - Corncob2061 on 10 Feb 2019 12:11:20 AM
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beertracker
Cochise

429 Posts

Posted - 10 Feb 2019 :  7:03:14 PM  Show Profile  Reply with Quote
quote:
Originally posted by Corncob2061

I asked Jim Butler about this once for using the old rods. He said they did use to use them in some high hp stuff years and years ago because they were lighter than the Early SD rods. But he followed that statement by saying they spent well north of 1000 dollars to run them. Some place in Texas worked then over for them. IRC, they x rayed, shot peened and heat treated them. Jay



I suppose x-ray will find internal cracks? How common is it for a shop to have x-ray capability? bt
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Corncob2061
Cochise

USA
467 Posts

Posted - 10 Feb 2019 :  7:47:51 PM  Show Profile  Reply with Quote
To be honest, I could be wrong about x raying, that is more something they do at a foundry I believe. I thought that is what he said. I think he said they checked the grain of the metal in the rods. It was above anything I have ever heard of for prep work, and it was $$$$. I remember it was some place in Texas. Since they are out of Tennessee, it was certainly not something everyone could do. It was a little over a year ago when I talked to Butler, and I have no idea how we got to talking about the old rods. He said that even after they did all the work to the early rods they still were not very strong. Jay
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p.rat
Two Feathers

USA
29 Posts

Posted - 22 Mar 2019 :  11:27:18 PM  Show Profile  Reply with Quote
Very interesting read! Something to remember is that a casting is a casting, and a forging a forging. Everything else being equivalent, i.e. material, size, shape, mass, etc., a forging is inherently stronger than casting. This is because the forging process forces the microscopic grain structure of the material to "flow/lay" in the same direction. Whereas, a casting's grain structure is random, making it much easier to be torn apart.

Another consideration is the material that is produced in China. It is well known in the auto industry that some Chinese material can be very suspect! Who knows what gets thrown into a batch of thier steel? Just like that bowl of Chinese food you are about to eat at the local buffet!!!
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